The objective of this research is to investigate the system of iron transport in fungi by genetic and biochemical methods, with Neurospora crassa as the principal, but not sole, research organism. Among other goals, we propose to identify the siderophore receptors in the plasma membranes of conidia and mycelium; understand why conidial siderophores are released at low water activities; discover the functional significance of the various intracellular and extracellular siderophores; and investigate the genesis and properties of the active transport system for siderophores. We wish to understand the biology and chemistry of this system and ultimately to apply this knowledge to the design of anti-fungal agents.